/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.ignite.configuration;
import java.io.Serializable;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Map;
import javax.cache.CacheException;
import javax.cache.configuration.Factory;
import org.apache.ignite.internal.util.typedef.F;
/**
* Factory implementation that use reflection to create instance of given class.
* <p>
* There are 2 modes of factory: singleton and non-sigletton.
* <p>
* Class that should be created by {@link IgniteReflectionFactory} (component class) have to be
* public java POJO with public setters for field
* for which property injection will be used (see {@link #setProperties(Map)}).
* <p>
* <h1 class="header">Configuration</h1>
* <h2 class="header">Mandatory</h2>
* The following configuration parameters are mandatory:
* <ul>
* <li>Component class - class to be created (see {@link #setComponentClass(Class)}.
* It have to be public java POJO class with default constructor
* and public setters to be used by properties injection (see {@link #setProperties(Map)})</li>
* </ul>
* <h2 class="header">Optional</h2>
* The following configuration parameters are optional:
* <ul>
* </li>
* <li>Singleton mode (see {@link #setSingleton(boolean)})</li>
* <li>Properties map (see {@link #setProperties(Map)}</li>
* <li>With method (see {@link #setWithMethod(Object, String, Serializable)}</li>
* </ul>
* <h2 class="header">Java Example</h2>
* <pre name="code" class="java">
* Factory<CacheStoreSessionListener> factory =
* new IgniteReflectionFactory<CacheStoreSessionListener>(MyCacheStoreSessionListener.class);
*
* CacheConfiguration cc = new CacheConfiguration()
* .setCacheStoreSessionListenerFactories(factory);
*
* IgniteConfiguration cfg = new IgniteConfiguration()
* .setCacheConfiguration(cc);
*
* // Start grid.
* Ignition.start(cfg);
* </pre>
* <h2 class="header">Spring Example</h2>
* TcpDiscoverySpi can be configured from Spring XML configuration file:
* <pre name="code" class="xml">
* <bean id="grid.custom.cfg" class="org.apache.ignite.configuration.IgniteConfiguration">
* ...
* <property name="cacheConfiguration">
* <list>
* <bean class="org.apache.ignite.configuration.CacheConfiguration">
* ...
* <property name="cacheStoreSessionListenerFactories">
* <list>
* <bean class="org.apache.ignite.configuration.IgniteReflectionFactory">
* <property name="componentClass" value="custom.project.MyCacheStoreSessionListener"/>
* </bean>
* </list>
* </property>
* ...
* </bean>
* </list>
* </property>
* ...
* </bean>
* </pre>
* <p>
* <img src="http://ignite.apache.org/images/spring-small.png">
* <br>
* For information about Spring framework visit <a href="http://www.springframework.org/">www.springframework.org</a>
* @see Factory
*/
public class IgniteReflectionFactory<T> implements Factory<T> {
/** */
private static final long serialVersionUID = 0L;
/** Singletom mode */
private volatile boolean singleton;
/** Component class */
private volatile Class<? extends T> cls;
/** Properties */
private volatile Map<String, Serializable> props;
/** */
private transient T instance;
/**
* Default constructor.
*/
public IgniteReflectionFactory() {
// No-op.
}
/**
* @param cls Component class.
* @param singleton Singleton flag.
*/
public IgniteReflectionFactory(Class<? extends T> cls, boolean singleton) {
this.cls = cls;
this.singleton = singleton;
}
/**
* Creates non-singleton component factory.
*
* @param cls Component class.
*/
public IgniteReflectionFactory(Class<? extends T> cls) {
this(cls, false);
}
/**
* @return {@code True} if factory is singleton.
*/
public boolean isSingleton() {
return singleton;
}
/**
* @param singleton Singleton flag.
*/
public void setSingleton(boolean singleton) {
this.singleton = singleton;
}
/**
* @return Component class to create.
*/
public Class<? extends T> getComponentClass() {
return cls;
}
/**
* @param cls Component class to create.
*/
public void setComponentClass(Class<T> cls) {
this.cls = cls;
}
/**
* Gets a map of properties. Map contains entries of component class field name
* to value of the filed which will be used as initial value.
*
* @return Properties.
*/
public Map<String, Serializable> getProperties() {
return props;
}
/**
* Sets a map of properties. Map contains entries of component class field name
* to a value of the filed which will be used as initial value.
*
* @param props Properties.
*/
public void setProperties(Map<String, Serializable> props) {
this.props = props;
}
/** {@inheritDoc} */
@Override public T create() {
synchronized (this) {
if (singleton) {
if (instance == null)
instance = createInstance();
return instance;
}
return createInstance();
}
}
/**
* @return Initialized instance.
*/
private T createInstance() {
if (cls == null)
throw new IllegalStateException("Failed to create object (object type is not set).");
try {
T obj = cls.newInstance();
injectProperties(obj);
return obj;
}
catch (InstantiationException | IllegalAccessException e) {
throw new CacheException("Failed to instantiate factory object: " + cls.getName(), e);
}
}
/**
* @param obj Object to initialize with properties.
*/
private void injectProperties(T obj) {
if (!F.isEmpty(props)) {
for (Map.Entry<String, Serializable> entry : props.entrySet()) {
String fieldName = entry.getKey().trim();
if (fieldName.isEmpty())
continue;
Serializable val = entry.getValue();
setWithMethod(obj, fieldName, val);
}
}
}
/**
* @param obj Object to initialize with properties.
* @param fieldName Field name.
* @param val Value to set.
* @return {@code True} if property was set.
*/
private boolean setWithMethod(T obj, String fieldName, Serializable val) {
StringBuilder sb = new StringBuilder("set");
sb.append(fieldName);
sb.setCharAt(3, Character.toUpperCase(sb.charAt(3)));
Class paramCls = val.getClass();
while (paramCls != null) {
try {
Method mtd = obj.getClass().getMethod(sb.toString(), paramCls);
mtd.invoke(obj, val);
return true;
}
catch (InvocationTargetException e) {
throw new CacheException(e.getCause());
}
catch (NoSuchMethodException | IllegalAccessException ignore) {
// try next class.
paramCls = paramCls.getSuperclass();
}
}
// Try interfaces.
for (Class<?> itf : val.getClass().getInterfaces()) {
try {
Method mtd = obj.getClass().getMethod(sb.toString(), itf);
mtd.invoke(obj, val);
return true;
}
catch (InvocationTargetException e) {
throw new CacheException(e.getCause());
}
catch (NoSuchMethodException | IllegalAccessException ignore) {
// try next interface.
}
}
return false;
}
}